Identification of race-specific resistance in North American Vitis spp. limiting Erysiphe necator hyphal growth.

Race-specific resistance against powdery mildews is well documented in small grains but, in other crops such as grapevine, controlled analysis of host-pathogen interactions on resistant plants is uncommon. In the current study, we attempted to confirm powdery mildew resistance phenotypes through vineyard, greenhouse, and in vitro inoculations for test cross-mapping populations for two resistance sources: (i) a complex hybrid breeding line, 'Bloodworth 81-107-11', of at least Vitis rotundifolia, V. vinifera, V.

Development of marker sets useful in the early selection of Ren4 powdery mildew resistance and seedlessness for table and raisin grape breeding.

The single, dominant powdery mildew resistance locus Ren4 from Vitis romanetii prevents hyphal growth by Erysiphe necator. Previously, we showed that when introgressed into V. vinifera in the modified BC(2) population 03-3004, Ren4 was linked with the simple sequence repeat marker VMC7f2 on chromosome 18-a marker that is associated with multiple disease resistance and seedlessness.

Genome expansion and gene loss in powdery mildew fungi reveal tradeoffs in extreme parasitism.

Powdery mildews are phytopathogens whose growth and reproduction are entirely dependent on living plant cells. The molecular basis of this life-style, obligate biotrophy, remains unknown. We present the genome analysis of barley powdery mildew, Blumeria graminis f.

A single dominant locus, ren4, confers rapid non-race-specific resistance to grapevine powdery mildew.

In the present study we screened the progeny of Vitis vinifera × V. romanetii populations segregating for resistance to powdery mildew and determined the presence of a single, dominant locus, Ren4, conferring rapid and extreme resistance to the grapevine powdery mildew fungus Erysiphe necator. In each of nine Ren4 pseudo-backcross 2 (pBC(2)) and pBC(3) populations (1,030 progeny), resistance fit a 1:1 segregation ratio and overall segregated as 543 resistant progeny to 487 susceptible.

Genomic amplification of the Gret1 retroelement in white-fruited accessions of wild vitis and interspecific hybrids.

Retrotransposons are retrovirus-related mobile sequences that have the potential to replicate via RNA intermediates and increase the genome size by insertion into new sites. The retroelement, Gret1, has been identified as playing a key role in generating fruit color variation in cultivated grape (Vitis vinifera L.) due to its insertion into the promoter of VvMybA1.

Wine grape (Vitis vinifera L.) color associates with allelic variation in the domestication gene VvmybA1.

During the process of crop domestication and early selection, numerous changes occur in the genetic and physiological make-up of crop plants. In grapevine (Vitis vinifera) numerous changes have occurred as a result of human selection, including the emergence of hermaphroditism and greatly increased variation in berry color. This report examines the effect of human selection on variable skin color by examining the variation present in the gene VvmybA1, a transcriptional regulator of anthocyanin biosynthesis.

Differential gene expression in Phaseolus vulgaris I locus NILs challenged with Bean common mosaic virus.

The Phaseolus vulgaris I locus-Bean common mosaic virus (BCMV; Potyviridae) pathosystem is of critical importance to bean geneticists, breeders and pathologists because of the worldwide distribution of both the virus and germplasm containing this resistance gene. In order to learn more about the molecular responses characteristic of this resistance gene, a cDNA-AFLP screen was conducted on homozygous NILs of P. vulgaris variety 'Black Turtle Soup' (BT), containing either the I locus allele for resistance (BT(II)) or susceptibility (BT(ii)) to BCMV.